1. Field of the Invention
This invention relates to novel clumpable animal litters.
2. Information Disclosure Statement including Description of Related Art
The following information is disclosed in accordance with the provisions of 37 CFR 1.56, 1.97 and 1.98.
As is well-known, many species of animals and birds are raised and/or kept by people for various purposes, e.g., as pets; for the production of valuable products such as food or furs; or for experimental purposes. A major problem connected with the raising and/or keeping of animals is the disposition of their waste excretions, mainly urine and feces. Whether the animal or bird is caged, in which case its waste is deposited on the floor of the cage, or allowed to roam free but is trained to deposit its waste in a particular receptacle, a "litter" material is generally employed which is capable of absorbing the liquid portion of waste excretions, primarily urine and the excess liquid of fecal matter.
Of particular interest as the basic component of animal litters are the clayey soils or comminuted rocks, e.g. the sodium bentonites, comprising at least one water-swellable clay mineral in the montmorillonite clay family, since these materials have the ability to clump and harden after contact with an aqueous liquid such as urine. This facilitates the removal of only the soiled portion of the litter in a litter box or cage during cleaning without the necessity of removing all the litter. However, while the water absorption properties of litters based on water-swellable clay make them more effective in reducing the mess of animal waste excretions between cleanings, due to the tendency of the clay to form clumps, it has been found that such clumps often tend to disintegrate before proper disposal. This decreases the effectiveness of the cleaning process.
With regard to the odor problem connected with the use of animal litters, various deodorizing agents have been recommended for use in such litters, including sodium bicarbonate (SBC). However, when SBC is utilized in the form of an unmodified powder as a deodorizing agent in animal litter, it tends to "wick" and dissolve in the aqueous phase of any animal waste products present, in which dissolved state it does not exert any deodorizing effect. Furthermore, due to its relatively high density, it tends to sink to the bottom of any litter composition present in the cage or litter box. To overcome these disadvantages, it has been proposed that the SBC be utilized in the animal litter in encapsulated form. However, the preparation of encapsulated SBC is an expensive procedure which renders the employment of SBC in this form impractical for many applications.
The following prior art references illustrate aspects of the technology of animal litter preparation, and, in particular, disclose the use of clays in such litters.
U.S. Pat. No. 3,765,371 issued Oct. 16, 1973 to Fisher, discloses a foamed plastic for absorbing and/or adsorbing animal waste products and also identifies clay and bentonites as previously used animal litters.
U.S. Pat. Nos. 4,275,684 issued Jun. 30, 1981 and 4,395,357 issued Jul. 26, 1983 to Kramer et al., disclose calcium silicate as an animal litter box absorbent material, and state that clay minerals, e.g. sepiolites, are known litters.
U.S. Pat. No. 4,315,761 issued Feb. 16, 1982 to Larrson et al., teaches the use of aerated or foamed concrete to absorb animal waste products and facilitate the removal of excrement from a litter box, and also discloses that "porous granulates of burnt expanded clay" is known for use as a urine absorbent.
U.S. Pat. No. 4,494,481 issued Jan. 22, 1985 to Rodriguez et al., discloses the addition of a soluble salt of a transition metal from Group Ib or IIb of the Periodic Table to a conventional litter composition to prevent the development of urine odors, and also identifies "clay such as . . . montmorillonites or bentonites" as suitable for use as an animal litter.
U.S. Pat. No. 4,570,573 issued Feb. 18, 1986 to Lohman, discloses an animal litter composition containing 60-94 wt. % of paper, 1-35 wt. % of gypsum, and 3-12% of water, and also states that clay, fuller's earth, and vermiculite are employed in cat litter compositions.
U.S. Pat. No. 4,638,763 issued Jan. 27, 1987 to Greenberg, teaches the addition of sodium sulfate to a litter box absorbent material to facilitate removal of solid absorbent material from the litter box, and teaches that clays such as montmorillonite and hectorite are suitable as absorbent material.
U.S. Pat. No. 4,685,420 issued Aug. 11, 1987 to Stuart, discloses an animal litter composition comprising a water-absorbing polymer such as a polyacryate combined with a porous inert solid substrate such as clay.
U.S. Pat. No. 5,000,115 issued Mar. 19, 1991 to Hughes, discloses the use of a water swellable bentonite clay as an absorbent litter material. The clay absorbs the liquids in animal waste which on contacting the clay agglomerates it into a stable mass easily separated from the unwetted and unsoiled portion of the composition.
Pending application Serial No. 08/056,511, filed May 3, 1993, discloses and claims the deodorizing additive which may be used in the litter compositions of this invention.
Pending application Serial No. 08/056,629, filed May 3, 1993, discloses and claims animal litter compositions containing a water-swellable clay and the deodorizing additive component which may be used in the litter compositions of this invention.